Just Do Not Forget
Those with a Virginia Concealed Handgun Permit MAY have your gun anywhere it is accessible to you, in an unlocked console or glove box, in the door pocket, under the seat, under your leg, or anywhere else.
But, you are responsible to control or mange the loaded gun at all times. So consider what happens if you get in accident, or make a rest stop, or get out to pump some gas. Or what happens when your trip is finished and you are leaving your car. Will you remember to "strap it on" again?
When you first begin to carry concealed you are constantly aware that you have a loaded gun with you. But after some time it becomes second nature and your awareness is diminished when potential threat levels are low.
I have found when around other people such as a rest stop or gas station my alertness is increased and I do strap it back on. The times I forgot and left it in the car were when I was home and the threat level was minimal. I suppose if your car is locked in your garage that there is some security and safety, unless you have kids around or adults who are not firearms savvy - then what? Leaving your loaded gun around for someone else to discover is always BAD.
So consider developing a memory jogger to remind yourself that you have placed your gun somewhere in the car. Perhaps put your pocket change in a different pocket from normal, or put your wallet in a different pocket. Something that feels different and will remind you, Oh yeah, do not forget the gun.